IMPREGNATION OF TISSUES WITH AROMATIC PRODUCTS

Abstract: A method of impregnating tissues with an aromatic product comprises packing the tissues in a substantially sealed container together with a quantity of a volatile liquid form of the aromatic product, the volatile liquid being contained on an absorbent base which is separated from the tissues by means of a film which prevents the flow of liquid from the base to the tissues but permits the evaporation of the volatile liquid to liberate the aromatic products for absorption by the tissues. Preferably, the base is located in an envelope formed of the film whereby the film and base together form a sachet. In the case where the container is a cylinder and the tissues take the form of an open-centred roll the sachet is preferably located within the open centre of the roll.

Description: IMPREGNATION OF TISSUES WITH AROMATIC PRODUCTS This invention relates to the impregnation of tissues with aromatic products, and to a package of tissues impregnated with aromatic products. For various reasons, it is desirable to provide tissues which are impregnated with an aromatic product. The term "aromatic" as used herein is used to indicate a product having an aroma, rather than in the strictly chemical sense of indicating an organic compound having an unsaturated ring containing alternating double and single bonds. Where it is desirable or acceptable for the impregnated tissue to be "wet" the application of the aromatic product can be accomplished by incorporating the aromatic product within the wetting liquid which is applied to the tissue. However, it is desirable for certain applications for the impregnated tissues to be "dry" - that is to have only a natural or close to natural water content, and not be wetted by a non-aqueous liquid. One means of achieving impregnation of dry tissues with aromatic products is to seal the tissues into a container in which a quantity of the aromatic product, in volatile liquid form, is contained. Over a certain period of maturation the volatile material evaporates and the aromatic products impregnate the tissues. With such a process, it is highly desirable that the volatile liquid does not come into direct contact with the tissues. If it does, and if the tissues are used after a relatively short maturation period there is a danger that excessive aromatic materials may be contained in relatively few of the tissues adjacent to the point of liquid contact, whilst the other tissues do not have sufficient aromatic content. Further, if at the time of use volatile liquid is still present on a tissue this may come into contact with the skin and cause an undesirable reaction. This is particularly the case if, for example, the product is intended for use by a person suffering from a cold and the tissue is applied to inflamed skin around the nose. Under these circumstances, if a liquid volatile ingredient such as camphor or menthol is present on the tissue a painful reaction with the skin can occur. With a view to avoiding direct contact between the volatile liquid and the tissues the prior art provided a technique whereby the volatile liquid is deposited onto a cotton wool ball located in the bottom of an empty container, a plastic spacer was placed on top of the cotton wool ball, and a roll of tissues was placed in the container to rest on top of the spacer. The container was then sealed and the entire package stood for an appropriate maturation period. During the maturation period the volatile liquid evaporated from the cotton wool and the vapour passed through apertures provided in the spacer to impregnate the tissues. Whilst such a technique does substantially avoid the danger that volatile liquid will come into direct contact with the tissues, the technique has a number of disadvantages. Firstly, the technique does not absolutely guarantee separation of the volatile liquid from the tissues since if the containers are stacked on their side or upside down volatile liquid may leak from the cotton wool to contaminate the tissues. An additional problem is that the technique requires a relatively long maturation period since evaporation of the volatile liquid from the space below the spacer, and migration of the resultant vapour into the tissues, is relatively slow. Finally, the need to provide the spacer increases the cost of the product and the need to provide a space between the spacer and the base of the container increases the overall height of the container with a further corresponding increase in costs. The present invention is accordingly concerned with a reliable and effective method of impregnating tissues (particularly but not exclusively dry tissues) with an aromatic product in a manner which substantially eliminates any risk that a volatile liquid form of the aromatic product comes into contact with any of the tissues. According to one aspect of the present invention there is provided a method of impregnating tissues with an aromatic product comprising packing the tissues in a substantially sealed container together with a quantity of a volatile liquid form of the aromatic product, the volatile liquid being contained on an absorbent base which is separated from the tissues by way of a film which prevents flow of liquid from the base to the tissue but permits the evaporation of the volatile liquid to liberate the aromatic product to portions of the container housing the tissues. According to another aspect of the invention there is provided a container of tissues, the container being substantially sealed to define an internal chamber in which the tissues are housed, the chamber also housing an absorbent base containing a volatile liquid form of an aromatic product; and means separating the base from the tissues, the separating means preventing flow of volatile liquid from the base to the tissues but permitting passage of evaporated aromatic products from the base to the tissues. Preferably, the means separating the absorbent base from the tissues comprises a film, preferably a polyolefin film which is perforated to provide one-way liquid flow characteristics. Such materials are commercially available for use as one-way barriers in sanitary towels, incontinence pads, and the like. It has been found that such materials are particularly suited to use as a barrier between the absorbent base and the tissues in the present invention. In an embodiment of the invention the absorbent base is located in the bottom of the container and is covered by the separating means. The-tissues may then rest on the separating means or on a spacer located to maintain separation between the separating means and the tissues. However, in the particularly preferred embodiment of the invention the absorbent base is contained within an envelope of the separating means to form a sachet. This arrangement is particularly desirable since the sachet can be separately manufactured and impregnated and then dropped into the container with the tissues. This considerably simplifies production of containers of tissues and by eliminating the need for a spacer reduces the cost of production since the spacer itself need no longer be provided and the additional container height necessary to provide a space between the spacer and the base of the container is no longer required. The advantages of the invention in terms of simplifying production are particularly apparent when the container is a right circular cylinder or a cylinder of elliptical cross-section and the tissues take the form of a roll having an open central region, the tissues being withdrawn in use from the centre of the roll. In this case, each container may be loaded with a roll of tissue and a sachet by suitable automatic machinery, and the containers sealed. The entire production process is highly suited to automation and provides significant savings as compared with the conventional package referred to above. Further, it has been found that a package of this type (i.e. a cylindrical container housing an open centred roll and a sachet) offers considerable advantages as compared with the prior art in terms of both the quantity of volatile liquid required to achieve a given level of impregnation of the tissues, and the maturation time required to achieve a given level of impregnation. Comparative tests of identical containers one of which, in accordance with the prior art, has a dose of volatile liquid charged onto cotton wool which is then separated from a roll of tissue by a plastic spacer, and the other of which, in accordance with an embodiment of the invention, contains a roll of tissue into the open centre of which a sachet charged with volatile liquid is placed, have shown that, for the same maturation period, tissues from the embodiment of the invention have contained almost double the concentration of aromatic products as compared with tissues from the conventional package, where both packages are initially charged with the same quantity of volatile liquid. Further, almost identical levels of concentration in the tissues of the two packages can be obtained after a given maturation period if the volatile liquid charge to the sachet is reduced to half of that in the conventional package. These results were obtained after a maturation period of six months for both containers. In further tests packages as described above were prepared using the same charge of volatile liquid in both the prior art package and the package according to the present invention, and the packages were matured for a period of one month. Analysis of the tissues showed that in the case of the packages according to the present invention the concentration of aromatic material in the tissues was at least 90% greater than that in the tissues of the prior art. Finally, sample packages were produced consisting of a package of the prior art as described above and a package according to the present invention in which the sachet contained half of the volatile liquid content of the conventional package. Analysis of tissues from the respective packages showed that tissues from the package according to the present invention achieve aromatic content levels after two weeks comparable with those achieved by the package of the prior art after four weeks. The above tests show that the invention will permit substantial additional savings in costs by allowing the amount of liquid volatile material, and the maturation time, to be reduced as compared with those of the prior art whilst still achieving concentrations of aromatic material in the dry tissues comparable if not better than those of the prior art. These savings, combined with the simplified manufacturing technique and the fact that the requirement for a plastic spacer is obviated lead to considerable cost savings. The absorbent base may be of any suitable material consistent with the nature of the volatile liquid. For example, the base may be of cotton wool, cellulose wadding, or comminuted wood pulp. The separating means may be any suitable material, for example GRADE PERFOLEN LR28 available from Heinrich Remshardt of Werderstr. 32, 2000 Hamburg 13, Germany. The tissues may be of any convenient form. The container may be in any convenient form and may, for example, be in the form of a can, plastic moulding, lined cardboard tube, or plastic sachet. In the case of the preferred embodiment of the invention where the base material is contained within an envelope of the separating means to form a sachet, conventional sachet forming techniques may be used to produce the sachets which may be wetted with the required volatile liquid either during manufacture or after formation since the one-way characteristics of the envelope material will permit volatile liquid to flow into the sachets from a suitable source even after the sachets have been formed. The invention is applicable to a wide range of aromatic products and by way of example, without limitation, such goods as Eucalyptus Oil, Menthol, Thymol, Camphor, Nutmeg and Pine Oils, Borneol, Methyl Salicylate, and Lavender Oil may be used alone or in combination to produce tissues suitable for relief of nasal congestion. However, it should be appreciated that the invention is not limited to the production of tissues for relief of nasal congestion and by suitable choice of aromatic product the invention may be applied to a wide range of applications, as for example in aromatherapy. For aromatherapy uses such products as Lavender, Tea-tree, Neroli, Bergamot, Camomile, Ylang Ylang, Orange, Lemon, Lemongrass, Rosemary, Rosewood and Rose, Camphor, Eucalyptus and Peppermint may be used alone or in combination.

Claims: CLAIMS 1. A method of impregnating tissues with an aromatic product comprising packing the tissues in a substantially sealed container together with a quantity of a volatile liquid form of the aromatic product, the volatile liquid being contained on an absorbent base which is separated from the tissues by way of a film which prevents flow of liquid from the base to the tissue but permits the evaporation of the volatile liquid to liberate the aromatic product to portions of the container housing the tissues. 2. A method according to claim 1 wherein the absorbent base is part of a sachet at least one wall of which is formed by the separating means. 3. A method according to claim 2 wherein the container is substantially cylindrical and comprising the steps of loading into the container a roll of tissues having an open central region, and inserting the sachet into the open central region of the roll prior to sealing the container. 4. A container of tissues, the container being substantially sealed to define an internal chamber in which the tissues are housed, the chamber also housing an absorbent base containing a volatile liquid form of an aromatic product; and means separating the base from the tissues, the separating means preventing flow of volatile liquid from the base to the tissues but permitting passage of evaporated aromatic products from the base to the tissues. 5. A container of tissues according to claim 4 wherein the absorbent base forms part of a sachet at least one wall of which is formed by the separating means. 6. A container of tissues according to claim 5 wherein the sachet comprises the base and an envelope formed of the separating means. 7. A container of tissues according to any preceding claim wherein the separating means comprises a perforated polymeric film, preferably a perforated polyolefin film. 8. A container of tissues according to any preceding claim wherein the base comprises cotton wool or cellulose wadding or comminuted wood pulp or a combination of these materials. 9 A container of tissues according to any of claims 4 to 9 wherein the aromatic product comprises Eucalyptus Oil, Menthol, Thymol, Camphor, Nutmeg and Pine Oils, Borneol, Methyl Salicylate, or Lavender Oil or a combination of these products. 10. A container of tissues according to any of claims 4 to 8 wherein the aromatic product comprises Lavender, Tea-tree, Neroli, Bergamot, Camomile, Ylang Ylang, Orange, Lemon, Lemongrass, Rosemary, Rosewood and Rose, Camphor, Eucalyptus and Peppermint or a combination of these products.

Inventors: HARGREAVES NIGEL, HARGREAVES, NIGEL
Applicants: HARGREAVES NIGEL, ROBINSON & SONS LTD, HARGREAVES, NIGEL, ROBINSON & SONS LIMITED
Application year: 1994
Main classification: A61K7
IPC codes: A47K7, A47K10, A61K8, A61L9, A61Q13